TNT分子印迹聚合物微球的合成与性能研究

以三硝基甲苯(TNT)为模板分子,EDMA为交联剂,采用沉淀聚合法制备了TNT分子印迹微球.讨论了溶剂用量、模板分子用量、功能单体种类等对分子印迹微球的形貌及吸附性能的影响;利用紫外吸收光谱和BET表征了印迹聚合物微球的结合位点相互作用与印迹孔穴结构;通过平衡吸附和选择性吸附实验,研究了印迹聚合物微球的吸附性能和选择性识别性能.结果表明,以丙烯酰胺为功能单体制备的分子印迹聚合物为规则的球形,内部含有分子印迹孔穴,微球的粒径为1～2μm.印迹聚合物微球可在30 min内达到吸附平衡,在1 mmol/L的TNT乙醇溶液中,印迹聚合物微球的平衡吸附量为32.5 mmol/kg,对TNT分离系数为25.19,具有较好的特异性吸附能力,并可选择性识别TNT分子.     

壬基酚表面印迹聚合物微球的合成及分子识别特性

采用表面分子印迹技术,在二氧化硅微粒表面通过乙烯基三甲氧基硅烷接枝,以壬基酚(NP)为模板、α-甲基丙烯酸为功能单体制备了壬基酚印迹聚合物。扫描电镜及比表面分析仪测试结果表明制备的印迹聚合物呈均匀分散的微球,具有较大的比表面积。采用红外光谱表征印迹聚合物微球制备过程中的化学结构变化情况,并用平衡吸附法研究了聚合物对NP的结合性能与分子识别特性。研究结果表明,聚合物对壬基酚具有良好的结合亲和性,最大结合量可达184.6 mg/g。印迹聚合物对NP的吸附量高于其结构类似物对特辛基酚和双酚A的吸附量,表现出较高的选择性识别能力。     

胆酸印迹聚合物的制备及在含水介质中的结合性能

为了在含水介质中进行有效印迹,本研究中以双甲基丙烯酰-β-环糊精（BMA-β-CD）和2-(二乙基胺基)乙基甲基丙烯酸酯(DEAEM)为功能单体制备了胆酸印迹聚合物MIP1,并用平衡结合实验研究了MIP1在含水介质中对模板分子的识别能力。结果表明,MIP1比单独以BMA-β-CD或DEAEM为功能单体制备的印迹聚合物MIP2和MIP3,显示出对模板分子更好的选择性结合能力。MIP1的特异性吸附量ΔCP为38.81μmol/g,印迹因子IF为2.46。研究表明,在含水介质中,利用模板分子与功能单体之间的疏水作用和离子作用是提高印迹聚合物分子识别能力的关键。研究还表明,在识别过程中,疏水作用在驱动分子进入印迹孔穴时起重要作用。     

铅离子印迹聚合物选择性吸附特性的研究与应用

利用离子印迹技术以铅离子为模板,甲基丙烯酸为功能单体,偶氮二异丁腈为引发剂,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备铅离子印迹聚合物。通过红外光谱和紫外光谱对该离子印迹聚合物进行表征,采用静态平衡吸附实验分析铅离子印迹聚合物的吸附性能和吸附选择性。实验结果表明:与非印迹聚合物相比较,Pb(II)印迹聚合物对Pb(II)具有较强的吸附能力和较好的吸附选择性,饱和吸附量为19.44mg/g,pH=6时吸附效果最好,达到吸附平衡的时间是7h;静态分配系数Kd和选择性系数k分别为1381ml/g和20.3。将该离子印迹聚合物应用于环境水样中铅离子测定时的预富集,结果满意。     

左氧氟沙星印迹聚合物微球及其特异吸附研究

以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合法制备了左氧氟沙星印迹聚合物(MIP)微球,用SEM和IR分别对微球形貌和结构进行表征,用静态吸附法和Scatchard分析考察了聚合物微球对模板及其结构类似物的吸附行为和选择性识别能力.结果表明,MIP对模板分子的吸附平衡速度快,40min即可达到吸附...     

功能微球PEI-CPGMA的制备及其对胆红素的吸附特性

以乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用悬浮聚合法制备了平均粒径为100 μm的交联聚甲基丙烯酸缩水甘油酯(CPGMA)微球,然后通过胺基与环氧键之间的开环反应,将聚乙烯亚胺(PEI)偶合接枝在微球表面,制得了表面接枝PEI的功能微球PEI-CPGMA.研究了功能微球对胆红素的吸附性能,考察了接枝度、介质pH、离子强度等因素对微球吸附性能的影响.静态吸附实验结果表明:功能微球对胆红素具有强吸附能力,等温吸附满足Freundlich吸附方程,饱和吸附量可达14.1 mg/g;介质的pH对微球吸附性能有很大的影响,在近中性(pH=6)溶液中,接枝微球对胆红素的吸附能力最强,而在酸性与碱性溶液中吸附能力都比较弱;离子强度对吸附作用表现出微弱的增效作用;微球表面PEI的接枝度越高,吸附能力越强.     

沉淀聚合法制备TNT分子印迹聚合物微球

以TNT为模板分子,丙烯酰胺为功能单体,二甲基丙烯酸乙二醇酯为交联剂,乙腈为溶剂,用沉淀聚合法制备了TNT分子印迹微球.紫外吸收光谱证实TNT与丙烯酰胺之间存在相互作用;平衡吸附实验结果表明,制备的分子印迹聚合物微球对TNT分子有较好的特异性吸附能力,能够选择性识别TNT分子.     

基于巯基乙酸与离子液体共修饰的过氧化氢生物传感器的研究

采用静电组装技术,将离子液体[Bmim]PF6与辣根过氧化物酶(HRP)交替固定在巯基乙酸修饰的金电极表面,制备了(HRP/[Bmim]PF6)n多层组装膜,并通过电化学阻抗谱(EIS)和傅立叶红外反射光谱(ATR-FTIR)对制备的组装膜进行了表征.以对苯二酚为电子媒介体,过氧化氢在(HRP/[Bmim]PF6)2双层组装膜传感器上的线性范围为1.6×10-6 ～2.5×10-3 mol/L,检出限为5.7×10-7 mol/L(S/N=3),达到95%稳态电流用时少于5 s,Kappm值为0.048 mmol/L,表明所固定的酶具有较高的生物活性.     

光接枝表面修饰法制备牛血红蛋白的分子印迹微球

聚苯乙烯球载体表面经引发转移终止剂修饰后, 采用光接枝表面印迹方法制备了以牛血红蛋白(BHb)为模板分子、丙烯酰胺为功能单体和N,N′-亚甲基双丙烯酰胺为交联剂的分子印迹聚合物微球(MIP). 进一步采用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物微球进行了表征, 证实了载体表面成功地接枝了分子印迹层, 并研究了其吸附性能和分子识别选择性能. 结果表明, 采用光接枝表面修饰法制备的分子印迹微球对模板分子有着很好的吸附容量和识别选择性.     

离子液体中酮肟O-烷基化反应的研究

以[Bmim]PF6,[Bmim]BF4,[Bmim]OH为介质,以NaOH为缚酸剂,由酮肟与卤烷、硫酸酯等烷基化剂在20～40℃反应1～2h,以52%～94%的收率制备了酮肟醚衍生物,产物结构经1HNMR,GC-MS表征.结果表明,该方法简便易操作,所用离子液体对环境友好,并可循环使用.     

悬浮聚合法制备磁性分子印迹聚合物微球

以苯胺和二甲基苯胺为模板分子、甲基丙烯酸(MAA)为功能单体、三羟甲基丙烷三丙烯酸酯(TRIM)为交联单体、Fe3O4为磁性组分,采用悬浮聚合法制备了磁性分子印迹聚合物微球(MMIPMs)。结果表明,改性Fe3O4微粒在MMIPMs中分散较好,MMIPMs在水性介质中对模板分子的选择吸附性较差,但在有机介质中有较好的选择吸附性。     

Synthesis and characterization of azoxystrobin hydrophilic molecularly imprinted microspheres

Abstract

In this research, hydrophilic molecularly imprinted microspheres (HMIPs) for azoxystrobin were successfully synthesized through precipitation polymerization. The adsorption capacities of HMIPs for azoxystrobin in water medium were higher than ordinary molecularly imprinted microspheres (MIPs), and HMIPs exhibited good hydrophilic properties. HMIPs and non-imprinted microspheres (HNIPs) were characterized by FT-IR, SEM, laser particle size analyzer and TGA. Comparing with HNIPs, azoxystrobin had a significant influence on morphologys and sizes of HMIPs. The Langmuir adsorption isotherm illustrated each binding site of HMIPs had the same adsorption capacity. The Lagergran pseudo-second-order kinetic model indicated the adsorption process between azoxystrobin and HMIPs was chemical adsorption. BET test illustrated HMIPs had bigger specific surface areas than HNIPs. Selective adsorption indicated that HMIPs had highly specific recognition of azoxystrobin. HMIPs successfully exhibited high selectivity and high hydrophilicity in water medium.     

Molecularly imprinted stationary phase prepared by reverse micro-emulsion polymerization for selective recognition of gatifloxacin in aqueous media

A new stationary phase for selectively recognizing gatifloxacin in aqueous media based on molecularly imprinted microspheres (MIMs) has been prepared by water/oil reverse micro-emulsion polymerization. The MIMs were prepared using gatifloxacin as the template, N, N'-methylenebisacrylamide as cross-linker and acrylamide and acryloyl-β-CD (β-CD-A, synthesized by ester reaction of acrylic acid with β-CD) as combinatorial functional monomers. The surface morphology of MIMs was characterized by scanning electron microscopy. The properties of MIMs recognition for gatifloxacin in water were studied by adsorption kinetics, adsorption isotherms combined with Scatchard analysis and selective recognition experiments. The results showed that the synthesized MIMs had an excellent ability to selectively recognize gatifloxacin in aqueous media. MIMs were employed as the chromatographic stationary phase to successfully separate the template gatifloxacin from its analogues. Discovering the mechanism of the MIMs recognition revealed that the memory cavities in the surface of the MIMs and hydrophobic effects between the template and the cavities of the β-CD residues were the primary contributions to the special recognition process.     

Solid-phase extraction of esculetin from the ash bark of Chinese traditional medicine by using molecularly imprinted polymers

A molecularly imprinted polymer solid-phase extraction method is used to extract esculetin from the ash bark of Chinese traditional medicine. Ratio of ethanol and water as washing solution were investigated. Data of accumulative adsorption on molecularly imprinted polymers from the continuous loading experiment suggests that there are two different kinds of recognition sites in molecularly imprinted polymers. By selecting the washing and eluting solution a scheme was designed to separate esculetin and its analogues including esculin, coumarin, 7-methoxylcoumarin and daphnetin. Finally, by applying the revised scheme esculetin was extracted from the ash bark of Chinese traditional medicine that was purchased from two big drugstores, respectively, with both molecularly imprinted polymers and non-molecularly imprinted polymers.     

Recognition of Staphylococcus enterotoxin via molecularly imprinted beads

The synthesis of molecularly imprinted beads for the recognition of the protein Staphylococcus enterotoxin B (SEB) is described. Two kinds of organic silane (3-aminopropyltrimethoxysilane (APTMS) and octyltrimethoxysilane (OTMS)) were polymerized on the surface of polystyrene microspheres after the SEB template was covalently immobilized by forming imine bonds. The resulting imprinted beads were selective for SEB. The Langmuir adsorption models were applied to describe the equilibrium isotherms. The results showed that an equal class of adsorption was formed in the molecularly imprinted polymer (MIP) with the maximum adsorption capacity of 3.86 mg SEB/g imprinted beads. The MIP has much higher adsorption capacity for SEB than the nonimprinted polymer, and the MIP beads have a higher selectivity for the template molecule.     

Molecularly imprinted ionic liquid magnetic microspheres for the rapid isolation of organochlorine pesticides in environmental water

A new type of molecularly imprinted ionic liquid magnetic microspheres was synthesized by aqueous suspension polymerization, using 4,4′‐dichlorobenzhydrol as a dummy template, and 1‐allyl‐3‐ethylimidazolium hexafluorophosphate and methacrylic acid as co‐functional monomers. The results of morphology and magnetic property evaluation of the obtained microspheres demonstrated that it was monodispersed spherical, possessed a rough surface, and an outstanding magnetic properties. Binding experiments revealed that it had a substantial adsorption capacity and strong recognition ability to organochlorine pesticides (OCPs) in aqueous solution. Then the microspheres were applied as an adsorbent of magnetic dispersive solid‐phase extraction for the selective recognition and rapid determination of OCPs in environmental water. Under the optimum conditions, good linearity of the three types of OCPs (dicofol, tetradifon, and p,p′‐dichlorodiphenyldichloroethane) was achieved in the range of 1.0–100 ng/mL (r ≥ 0.9994). The recoveries at three spiking levels ranged from 82.6 to 100.4% with the RSDs less than 6.9%.     

分子印迹胶体阵列检测对硝基苯酚

以对硝基苯酚(p-NP)为印迹模板,丙烯酰胺为功能单体,制备单分散的对硝基苯酚分子印迹胶体微球。通过垂直沉降法将分子印迹胶体微球自组装为分子印迹胶体阵列,采用胶带将分子印迹胶体阵列粘贴固定。固定于胶带上的分子印迹胶体阵列膜显示出良好的稳定性,而且对目标分子p-NP具有明显的光学响应。分子印迹微球吸附目标分子发生溶胀,引起胶体阵列溶涨,分子印迹胶体阵列(MICA)反射峰位置发生移动。实验结果显示,MICA随着p-NP浓度增加,反射峰红移近60 nm,MICA表面颜色由红色逐渐变为蓝紫色;而非印迹胶体阵列红移量只约40 nm。MICA简化了光子晶体凝胶传感材料的制备步骤,为开发新型高性能生化传感器材料提供了新思路。     

A new ionic liquid surface‐imprinted polymer for selective solid‐phase‐extraction and determination of sulfonamides in environmental samples

Toward improving the selective adsorption performance of molecularly imprinted polymers in strong polar solvents, in this work, a new ionic liquid functional monomer, 1‐butyl‐3‐vinylimidazolium bromide, was used to synthesize sulfamethoxazole imprinted polymer in methanol. The resulting molecularly imprinted polymer was characterized by Fourier transform infrared spectra and scanning electron microscopy, and the rebinding mechanism of the molecularly imprinted polymer for sulfonamides was studied. A static equilibrium experiment revealed that the as‐obtained molecularly imprinted polymer had higher molecular recognition for sulfonamides (e.g., sulfamethoxazole, sulfamonomethoxine, and sulfadiazine) in methanol; however, its adsorption of interferent (e.g., diphenylamine, metronidazole, 2,4‐dichlorophenol, and m‐dihydroxybenzene) was quite low. ¹H NMR spectroscopy indicated that the excellent recognition performance of the imprinted polymer was based primarily on hydrogen bond, electrostatic and π‐π interactions. Furthermore, the molecularly imprinted polymer can be employed as a solid phase extraction sorbent to effectively extract sulfamethoxazole from a mixed solution. Combined with high‐performance liquid chromatography analysis, a valid molecularly imprinted polymer‐solid phase extraction protocol was established for extraction and detection of trace sulfamethoxazole in spiked soil and sediment samples, and with a recovery that ranged from 93–107%, and a relative standard deviation of lower than 9.7%.     

Preparation of magnetic molecularly imprinted polymer nanoparticles by surface imprinting by a sol–gel process for the selective and rapid removal of di‐(2‐ethylhexyl) phthalate from aqueous solution

Magnetic molecularly imprinted polymer nanoparticles for di‐(2‐ethylhexyl) phthalate were synthesized by surface imprinting technology with a sol–gel process and used for the selective and rapid adsorption and removal of di‐(2‐ethylhexyl) phthalate from aqueous solution. The prepared magnetic molecularly imprinted polymer nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The adsorption of di‐(2‐ethylhexyl) phthalate onto the magnetic molecularly imprinted polymer was spontaneous and endothermic. The adsorption equilibrium was achieved within 1 h, the maximum adsorption capacity was 30.7 mg/g, and the adsorption process could be well described by Langmuir isotherm model and pseudo‐second‐order kinetic model. The magnetic molecularly imprinted polymer displayed a good adsorption selectivity for di‐(2‐ethylhexyl) phthalate with respect to dibutyl phthalate and di‐n‐octyl phthalate. The reusability of magnetic molecularly imprinted polymer was demonstrated for at least eight repeated cycles without significant loss in adsorption capacity. The adsorption efficiencies of the magnetic molecularly imprinted polymer toward di‐(2‐ethylhexyl) phthalate in real water samples were in the range of 98–100%. These results indicated that the prepared adsorbent could be used as an efficient and cost‐effective material for the removal of di‐(2‐ethylhexyl) phthalate from environmental water samples.     

分子印迹聚合物的制备及其对香草醛的吸附行为

以香草醛为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,制备了香草醛分子印迹聚合物(MIP);研究了以不同致孔剂合成的MIP在水溶液中对香草醛的吸附行为.结果表明,以乙腈为致孔剂合成的MIP对香草醛具有较高的识别特性,能较简便地用于香草醛的分离和富集.